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Flying over Water at Low Altitude

Fletcher500

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I have had about 5 flights over the ocean, with no problems. The lowest altitude was 25'.

I know a lot of people do it all the time, and posted some great vid's. I have read a few accounts where the Quad became confused by the water, and it went haywire. Is this a known problem?

Also, how low are others getting over the water?
 
Another thing that's been done "all the time" is posting a subject that has been answered many times...

But I must agree the search feature needs some improvement.

(too many same topics... The forum needs better sections!)
 
When flying low over water, it would be best to turn off the downward sensors in DJI GO. That'll prevent any confusion from the VPS. Reflections off the surface of the water can sometimes confuse the VPS, so turning it off when flying higher would be an okay practice to follow too.

DJI-GO-Downward-Vision-Positioning.jpg
 
Another thing that's been done "all the time" is posting a subject that has been answered many times...

But I must agree the search feature needs some improvement.

(too many same topics... The forum needs better sections!)
Agree on the search but doesn't need more sections just folks posting in the correct section and also skimming pages.
Also if members would report duplicate subjects instead of just complaining we could direct them to one. Or better yet
if you know of a thread you post it to the poster.
Back to topic
I fly over water a lot at 20' and tilt my camera down a little and gives it the effect of being lower. Also as msingers posted cut that sensor off.
 
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But I must agree the search feature needs some improvement.

Just an FYI on this comment... be sure you are using the advanced search if a basic search doesn't work for you.

Click the magnifying glass,
Screen Shot 2017-03-24 at 5.01.39 PM✨.png

then the gear,
Screen Shot 2017-03-24 at 5.01.53 PM✨.png

then click the 'more' button...
Screen Shot 2017-03-24 at 5.02.05 PM✨.png
 
Just be carefull if you are flying high speed in sports mode , remember that the aircraft tilts forward and you might misjudge the real altitute
 
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Also if members would report duplicate subjects instead of just complaining we could direct them to one. Or better yet
if you know of a thread you post it to the poster.

I'm sorry my point wasn't to complain... I'm pretty new myself but already see some patterns in new posts (which is of course the responsibility of everyone)

I think the following points may be the cause:

-checking the forum from the app doesn't allow easy access to some options (direct to post seems non-existent for example, as others)

-as I was wanting to check every time if my question has been asked, I must say the procedure seems difficult... (the search algorithm may be improved) therefore many same topics are constantly created. (I pretty much settled to create new without looking and that's shows improvement is needed)

My point is more to share my feelings instead of criticism... (sorry) but reporting should only be for bad behavior, not duplicated topics.

Anyway, improvement is constant...
 
When flying low over water, it would be best to turn off the downward sensors in DJI GO. That'll prevent any confusion from the VPS. Reflections off the surface of the water can sometimes confuse the VPS, so turning it off when flying higher would be an okay practice to follow too.

View attachment 9237

Are you saying never enable VPS ?
 
I'm saying you might not want to use it when flying over water. You could keep it enabled and monitor the VPS altitude displayed at the bottom of DJI GO. If you notice any odd values mid-flight, then disable it. Personally, I think it would be easiest to just disable it before taking off so you don't have to worry about monitoring it throughout the flight.
 
I'm saying you might not want to use it when flying over water. You could keep it enabled and monitor the VPS altitude displayed at the bottom of DJI GO. If you notice any odd values mid-flight, then disable it. Personally, I think it would be easiest to just disable it before taking off so you don't have to worry about monitoring it throughout the flight.

Thanks msinger that is a good tip for your giveaway but I have already suggested my tip. Lol
 
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Agr
When flying low over water, it would be best to turn off the downward sensors in DJI GO. That'll prevent any confusion from the VPS. Reflections off the surface of the water can sometimes confuse the VPS, so turning it off when flying higher would be an okay practice to follow too.

View attachment 9237
Agreed, When I fly over water over the ocean the Mavic will follow the contours of the sea. So if you have lots of swell the Mavic will move up and down following the ocean surface. I turn it off over water if I want smooth shots too.
 
Copy that, I will search next time.

I have read a few of the old threads and The VPS comments.

To clarify, turning it off is about preventing elevation changes as the quad flies over waves in regards to video? IE, bouncy video.

IE, if you are monitoring the elevation read out, Turning it off will not make the quads journey any safer in regards to confusion of the processor seeing water verses land below it?
 
With VPS disabled, your Mavic might be able to hold the altitude better when flying over water (when it's detecting the ground/water). Also, if you move the throttle stick to the full down position and the VPS thinks your Mavic is less than 0.5 meters from the ground (like when the sun reflects off the water), it'll switch to forced landing mode and start auto landing.
 
Thanks for the replies.

The key take away as I understand it, is the stick would have to be held fully down while it is only a few feet above the water in order for the auto landing feature to be engaged, thinking there is land below, as opposed to water.

Flying with VPS off (by consensus) is generally considered a good practice over water.

However, there do not appear to be many quads going for a swim when they are a decent distance (say 10 ft. or >) above the water with VPS on?

This quad is going to spend most of his time over the ocean, so just verifying I have this straight.
 
The key take away as I understand it, is the stick would have to be held fully down while it is only a few feet above the water in order for the auto landing feature to be engaged, thinking there is land below, as opposed to water.
The throttle must be in the full down position and the VPS altitude must be showing 0.5 meters or less in the DJI GO. The Mavic could be a hundred feet in the air and still trigger forced landing mode if the VPS estimates a false altitude reading (e.g. the sun light shining off the water and into the downward sensors).
 
The throttle must be in the full down position and the VPS altitude must be showing 0.5 meters or less in the DJI GO. The Mavic could be a hundred feet in the air and still trigger forced landing mode if the VPS estimates a false altitude reading (e.g. the sun light shining off the water and into the downward sensors).

Got it, thanks.

The key factor being "the throttle is in the full down position". I am having trouble seeing how anyone could end up in this situation because they would never have it in the full down position while in typical flying mode, unless they were landing it.

Are there are any know cases of quads doing this?

I get it, disable VPS over the ocean is what I will do. Just wondering if I, or one of my kids forgets what are the chances of losing it with it on.
 
But don't forget to enable VPS once you are flying back on solid ground. I forgot and when I went to land, I experienced a rather rough landing because the VPS wasn't sensing the driveway I was landing on.
 
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But don't forget to enable VPS once you are flying back on solid ground. I forgot and when I went to land, I experienced a rather rough landing because the VPS wasn't sensing the driveway I was landing on.


In the words of the famed scholar......DOH!!! :)
 
May be worth mentioning here that if leaving VPS on while flying over water with the latest FW, best to turn off landing protection. If the AC goes into landing mode with the latest FW (March 2, 2017), it cannot be canceled with full throttle up, unless the landing protection is off, or you very quickly switch from gps to sports mode, or sports to gps. I verified this today. Turning off landing protection just skips the .5 meter hold where you had to do a final landing confirmation. Still makes a very smooth landing. I leave landing protection off all the time now, at least until DJI corrects the problem with not being able to use throttle up to abort a landing.
 
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On the .400 firmware, I have been flying over slow rivers and lakes at 3-5 feet with no troubles with VPS enabled. Same for mild white water. Still haven't found a situation where it misbehaves over water in all lighting conditions. I'll continue to be diligent to see what conditions seem to trip up the VPS.
 
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